The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 13, 1977
Filed:
Jun. 14, 1976
Applicant:
Inventor:
Horst Hartmann, Nauborn, DT;
Assignee:
Ernst Leitz GmbH, Wetzlar, DT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
250201 ; 2502 / ; 3501 / ;
Abstract
Method and apparatus for automatically focusing an optical system, particularly a microscope. A grating is located in the intermediate image plane and acts as a spatial frequency filter. A photoelectric detection system is associated with the grating. Electrical control signals are generated which are modulated by the relative motion between the object image and the grating. This motion is preferably normal to the longitudinal range of the grating marks. The grating used is short compared to the range of the intermediate image. The relative motions extending across several grating constants are generated between the image and the grating.